Figure 13.24 (A) Soleus muscle controlling forward movement of the tibia. (B) Plantar flexors concentrically contract in a closed chain action to propel the body forward during walking.
Clinical Connection 13.4
The tendon of the posterior tibialis muscle can be involved in a progressive and incapacitating disorder called posterior tibial tendon dysfunction (PTTD). This condition affects approximately 5 million people in the United States each year and appears to have multiple factors that contribute to foot pain and walking dysfunction.
People with low medial longitudinal foot arches are at a higher risk for development of PTTD. Muscle weakness and poor gait biomechanics are also risk factors for development of the condition. Increased hindfoot eversion with resultant pronation is often observed in the walking patterns of individuals with PTTD. Other factors associated with PTTD include age-related degeneration, infl ammatory arthritis,
hypertension, diabetes mellitus, obesity, and acute trauma rupture.
The condition is characterized by three stages of progression. Stage I manifests with mild swell- ing, medial ankle discomfort, and pain during heel raises. In stage II, there is progressive lowering of the medial longitudinal foot arch with a secondary midfoot abduction deformity. In this stage, the pos- terior tibialis tendon is infl amed and elongated and can be ruptured. The rearfoot is still fl exible, but the patient cannot perform heel raises. Stage III manifests with the components of stage II, but now the rearfoot is fi xed in eversion. People in the early stages of this condition can benefi t from corrective orthoses and strengthening and stretching exercises.
